It's no secret that some content owners don't seem to understand how the DMCA works—that, or they simply don't care when sending mass takedown notices. This seems to be the case with the recent saga of legal maneuvers between the National Football League (NFL) and Brooklyn Law School professor Wendy Seltzer. The two have been going back and forth with DMCA-related "requests" since early February—with YouTube stuck in between—and in the process, the NFL itself appears to have violated the DMCA.
This is really interesting. It looks like the NFL screwed up, large..
This article is a good summary. You can also read Wendy's account of the situation on her blog.
NFL fumbles DMCA takedown battle, could face sanctions